Field of the Invention
The present invention generally relates to a multi-link engine. More specifically, the present invention relates to a vibration reducing structure that reduces vibration in a multi-link engine.
Background Information
Engines have been developed in which a piston pin and a crank pin are connected by a plurality of links (such engines are hereinafter called multi-link engines). For example, a multi-link engine is disclosed in Japanese Laid-Open Patent Publication No. 2006-207634. The multi-link engine of this patent publication is provided with an upper link and a lower link for connecting a piston to a crankshaft. The upper link is connected to a piston, which moves reciprocally inside a cylinder by a piston pin. The lower link is rotatably attached to a crank pin of a crankshaft and connected to the upper link with an upper link pin. A compression ratio of the multi-link engine is variably controlled by controlling an orientation of the lower link. The multi-link engine also has a control link with one end coupled to the lower link and the other end coupled to an eccentric portion of a control shaft. The orientation of the lower link is controlled through the control link by changing a rotational angle of the control shaft.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved multi-link engine that reduces vibration in the multi-link engine. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.